1. Field of Invention
This application relates, generally, to a method of providing information over an FM subcarrier frequency, and specifically to a revenue producing model of providing instant reporting of content specific information to commuters.
2. Background of Invention
When the FCC established the FM broadcast system, they assigned each station a channel with a width of 200 kHz. As an example, the station assigned to 88.1 Mhz (88,100 kHz) is authorized to use frequencies from 88,000 kHz to 88,200 kHz. When a tone of a certain frequency is transmitted over FM, the bandwidth of the transmitted signal is a minimum of twice that frequency. As such, frequencies of up to 100 kHz can be transmitted on an FM broadcast station. The average person can only hear frequencies up to 15 kHz, leaving an abundance of space on the FM transmitter for other signals.
To provide extra channels that could be sold by the FM stations in an effort to increase their revenue and offset their investment in equipment, the FCC created SCA. SCA stands for Subsidiary Communications Authorization. In the late '40s and early '50s, the FM band was not a major profit center for the broadcasters that had invested heavily in transmission equipment, and they asked the FCC for additional ways to leverage their investment. Some FM broadcasters played easy listening music and preceded all commercial breaks with a sub-audible tone. They then “sold” the signal to stores, with receivers that would mute the commercials when the tone was detected. The FCC outlawed this practice, saying that although it would be legal to build a radio that could detect commercials and dump them, it would not be legal for broadcasters to generate any kind of special signal on the air to identify commercials. But, this practice helped create a market for commercial background music. Originally, the commission specified very precisely the SCA frequencies and bandwidth that could be used and sold. Now, broadcasters are allowed to place any kind of signal, digital or analog, at any frequency or bandwidth, as long as it does not interfere with the main channel signal or extend the bandwidth of the FM station much beyond the 100 kHz allocation.
The frequencies from 19 kHz to 53 kHz are used for transmission of stereo. Thus, the frequencies from 53 kHz to 100 kHz are not usable for the transmission of SCA programming. SCA utilizes the frequency bands that center on 67 kHz and 92 kHz through the use of frequency modulation. These frequencies are well beyond human hearing range, and therefore have no effect on the reception of normal programming. A typical SCA channel is an FM carrier wave, basically a high-pitched whistle at 67 kHz or 92 kHz. At the SCA receiver, the subcarrier signal is demodulated and the information is heard by the user over the receiver speaker.
Transmission of an encoded signal with information separate from that of the material of the main signal has proven to be possible and realistic. In the 70's, many voice and data signals began to appear on SCAs. Agri-ports used voice channels and later data transmission to bring commodity prices to their network of grain elevators, brokers, etc. The Bonneville Corporation created a high-speed data service with commodity prices and many SCA broadcasts provided new and music in Chinese, Greek, Korean and various other languages.
During the 70's, the Physicians' Radio Network, transmitted news, short educational courses, live call-in shows, and reports from various medical associations to physicians and was available nationwide on SCA. The broadcast from the Physicians' Radio Network also included advertisements related to pharmaceutical products. Pharmaceutical Representatives distributed portable SCA receivers to physicians. As such, the Physicians' Radio Network (PRN) was a for-profit enterprise, financed by drug company advertising.
Traffic reports are provided by the radio and television media and are used by commuters to plan their routes. It is desirable to know the condition of the roads, potential congestion and accidents in advance of leaving for a destination. Existing reporting systems on the various media are inadequate to provide drivers with the information they need to plan their commute. Most commonly, drivers receive traffic congestion information over the radio. Traffic reports communicated via the radio have several disadvantages: the traffic report is not updated frequently, and therefore, inaccurate information is provided to the driver; the broadcast of the traffic report is not necessarily announced at the time the driver needs the information; due to their infrequency, traffic reports are easily missed or the driver may tune in while the report is in progress and pertinent information; and, the driver must interrupt other listening devices in the vehicle, such as CD players and tapedecks, to locate the traffic report on their car radio.
The ARI service utilizes a 57 kHz subcarrier frequency to broadcast voice messages regarding hazardous weather or traffic conditions. The voice message sent by this service is a continuous transmission. Tuning into a continuous transmission often results in missed information. The information is not available on-demand as controlled by the user. The ARI service has not been aggressively promoted by radio stations because it lacks the opportunity for revenue generation.
SCA receivers adapted to receive and demodulate FM subcarrier frequency broadcasts are well known in the art. U.S. Pat. No. 5,023,933, entitled “Superheterodyne SCA Receiver and Method for the Manufacture Thereof”, U.S. Pat. No. 5,193,213, entitled “FM Broadcast Band Subcarrier Receiver”, and several others provide various solutions to some of the problems associated with SCA receivers. Solutions have been provided to improve passband characteristics, reduce noise and distortion, and improve portable reception. ComPol, Inc. is a technology leader in SCA reception providing products for both the commercial and consumer market. ComPol, Inc. markets a 7×2.5×0.75 inch, battery operated, portable SCA receiver with a belt-clip.
U.S. Pat. No. 4,480,253, entitled “Portable Traffic Congestion Radio”, describes a method for presenting traffic condition information to a user by use of a portable, battery operated receiving and data processing device. However, this patent requires the use of digitally coded traffic reports and does not utilize the SCA frequencies for transmission of information.
While FM subcarrier receivers are well known in the art and various services are available that provide information utilizing the SCA frequencies, the combination of the known receivers and services does not provide a cost effective solution to an individuals need for instant, on-demand, content specific information. More specifically, the prior art solutions for supplying traffic information do not describe a method by which continuously updated traffic information is provided to drivers, on demand. Prior art solutions do not describe the importance of revenue generation to the adoption continued growth on an instant reporting system.
There remains a need, therefore, for a cost effective solution to provide continuous traffic information to drivers on an as-needed basis.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified need could be fulfilled.